Vacuum cleaner



FIG. 1 is a top perspective view of a vacuum cleaner showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left-side view thereof;

FIG. 4 is a right-side view thereof;

FIG. 5 is a top and left-side view thereof; and,

FIG. 6 is a top and right-side view thereof.

The details shown in broken lines form no part of the claimed design. 

The ornamental design for a vacuum cleaner, as shown and described. 